N/A
1. Field of the Invention
The present invention relates to marine electrical generators, and more particularly to an electrical generator adapted for installation on the transom of a marine vessel. Electrical power is generated by an internal combustion engine, including a submerged exhaust port for discharging combustion gases below water, and a permanent magnet alternator. The electrical generator provides a reliable and cost effective source of A/C and D/C electrical power for use aboard marine vessels.
2. Description of the Related Art
Marine vessels require power for many purposes. For example, a substantial amount of power is typically required for propulsion (i.e. power to drive the propeller). In addition, power is also required for onboard electrical service (i.e. lighting, communication and navigation electronics, etc.). As the power demands for propulsion and onboard electrical service vary widely, large vessels are often equipped with two separate power generation systemsxe2x80x94one for propulsion and one for electrical power. Small and medium size vessels, however, are often forced to rely on the limited supply of electrical power available from the engine that drives the primary propulsion system, such as the electrical power produced by an outboard motor. In situations where the primary means of propulsion is an outboard motor, the availability of electrical power is severely limited. As a result, small and medium size vessels are often forced to rely on an auxiliary portable generator unit as a source of electrical power. The use of portable generator units, however, presents a number of significant disadvantages including high cost, the presence of hot exhaust gases, excessive noise, difficult installations due to a lack of space, and the inability of transom mounting. Thus, the background art reveals a number of auxiliary power generation devices provided for use with outboard motors.
For example, U.S. Pat. No. 2,879,738, issued Mar. 31, 1959 (Culbertson), discloses a combined outboard motor and generating plant. The Culbertson reference discloses a generator mechanism comprising a rotating armature type device used to simultaneously propel a boat while generating electricity. U.S. Pat. No. 4,010,377, issued Mar. 1, 1977 (McKenzie), discloses a combined generator and boat propulsion system wherein the generator drive shaft is coupled to the propulsion unit drive shaft via a centrifugal clutch (16). McKenzie discloses an open framework device further provides a second/auxiliary drive sprocket (70). U.S. Pat. No. 4,695,261, issued Sep. 22, 1987 (Broughton), discloses a marine propulsion device having a voltage generator mounted thereto. Broughton discloses a configuration wherein the voltage generator is located in the recess in the underside of the flywheel and an annular power takeoff pulley (132) mounted on the flywheel. Broughton relies on a pulse generator (61) for the conventional capacitor discharge ignition circuit in addition to the power generator (63). U.S. Pat. No. 5,011,442, issued Apr. 30, 1991 (Polcz et al.), discloses an auxiliary power generation device for use in an outboard motor. Polcz et al. teach adapting an outboard motor by mounting an alternator coaxially with the flywheel to provide 1000 watts of D/C. power. The Polcz reference further discloses an available inverter for providing A/C power in addition to the D/C power supply.
The electrical generating devices of the background art, however, fail to provide a fully functional light weight outboard generator capable of being mounted on the transom and able to produce high quality and clean A/C and/or D/C electric power responsive to varying electrical loads while maintaining a substantially sound proof construction and a submerged exhaust.
The present invention provides an outboard marine electrical generator unit capable of installation on the transom of a marine vessel. The outboard generator according to the present invention provides an electrical generating unit for small and medium sized marine vessels (specifically power and sail boats in the 20-40 foot range) that are otherwise not equipped with an auxiliary electrical generator and/or do not have space available for the installation of a conventional onboard marine generator. The invention thus provides an A/C and D/C electrical power source capable of providing electrical power for appliances, air conditioning units and other electrical loads, even while the primary propulsion system is off and the vessel is docked or at anchor.
An outboard marine electrical generator according to the present invention includes the following primary components: (1) a outboard motor-type housing, including upper and lower portions, generally having the external appearance of an outboard motor but for the absence of a propeller; (2) an internal combustion engine; (3) a permanent magnet electrical generating assembly, including a rotor, a stator, and a cooling fan, mechanically connected to the engine crankshaft; (4) a carburetor assembly, including feedback control responsive to electrical load; (5) an inverter module, including pulse-width-modulation (xe2x80x9cPWMxe2x80x9d) voltage regulation system and D/C-A/C inverter frequency regulation system; (6) an exhaust system terminating at the lower housing portion in a typically submerged location; (7) a fuel storage and delivery system, including either an internal and/or external fuel tank and a fuel pump; and (8) a transom mounting mechanism, preferably including a tilt feature.
The above-referenced device provides a transom mountable marine outboard generator powered by a 4-stroke, single-cylinder gasoline engine that is capable of producing 1,000 VA at the following electrical ratings: 120 VAC/7.5 A/60 Hz and/or 12 VDC/8.0 A. The power supplied is sufficient to power, among other things, a 5,000 Btu marine air conditioning system for providing comfort cooling. The outboard generator weighs approximately 34 lbs. and is capable of operating for approximately 6 hours on a single gallon of gasoline. The outboard generator provides for the submerged discharge of exhaust thereby minimizing noise levels and reducing the likelihood that noxious exhaust fumes will accumulate in occupied parts of the vessel. Outboard generators according to the present invention may be fabricated with greater electrical generating capacities using larger horsepower engines.
It is an object of the present invention to provide a transom mounted electrical generator for marine vessels.
Still another object of the present invention is to provide a transom mounted marine electrical generator capable of producing both A/C and D/C electrical power for providing small and medium sized marine vessels with sufficient and cost effective power for running a variety of electrically operated devices including cabin air conditioning units, lights, computers and other electronic devices.